Encryption of American express card file in Expenses fusion

Summary:

I am implementing AMEX card integration to Oracle Expenses. And we checked with AMEX that it is ok to encrypt the transmission file. Therefore, we generate a PGP public key to AMEX.

However, from the implementer guide, there is a statement "PGP encryption isn't applicable to American Express".

May I know if AMEX card transaction file can be encrypted? Because I can see there is an encryption key alias when setting up the corporate card program.

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